The 29-year-old singer's collaborator Jack Antonoff has revealed the pop star had a huge hand in the new song.

He wrote on Twitter: ''did this one entirely at electric lady in NYC. only laura sisk and taylor in the room. taylor wrote every stitch of this song and came in and played it for me - just a perfect moment to hear what she had done alone the night before ... when someone brings in a song that speaks so much just on a piano it's rare to imagine production around. but then we started playing with space echo reverb on a snare hit really hard with a brush ... from there the ''paul'' bass happened and the washy piano. melotron in bride to sound like a dream sequence wedding. but the part i'm most proud of is her voice drowned in verb. cuts right through and sits all around you at the same time ... worked that night for about 6 hours and besides the mix all the tracks and takes are from then. live drum, bass, acoustic, 12 string, upright piano and melotron. all going through copycat and space echo. big mess until it's not (sic)''

Taylor is to release the video for 'Lover' next Thursday (22.08.19).

Speaking to fans in a video posted on social media, Taylor said: ''Hey guys, so I'm going love on YouTube on August 22nd at 5pm EST. It's going to be really fun, we're going to talk all things 'Lover', the Stella McCartney line, I'm going to do a performance of a song I've never performed before and then we're going to premiere the brand new music video for the song 'Lover'. So join us, please.''